添加剂对超重力下燃烧合成Al_2O_3/ZrO_2的影响  

Influence of Additive on Al_2O_3/ZrO_2(4Y) Composites Prepared by Combustion Synthesis under High Gravity

作　　者：宋亚林[1] 赵忠民[1] 张龙[1] 朱浩[1] 曲振声[1] 杨权[1] 

机构地区：[1]军械工程学院先进材料研究所

出　　处：《特种铸造及有色合金》2009年第1期63-66,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(50672131)

摘　　要：基于超重力下燃烧合成Al2O3/33ZrO2(4Y)复合陶瓷板,通过添加不同含量的SiO2,研究SiO2添加剂对Al2O3/33ZrO2(4Y)显微组织、晶体生长及力学性能的影响。XRD、SEM和EDS分析显示,SiO2的添加并未改变陶瓷物相组成;但是,随SiO2添加量的增加,陶瓷显微组织由胞状共晶团转变为棒状共晶组织,且棒状共晶团的长径比逐渐增大,而体积分数却随之下降。陶瓷相对密度因SiO2对陶瓷熔体粘度的双重影响,在SiO2的质量分数为6%时达到最高值,为97.4%;陶瓷硬度因SiO2在陶瓷中形成玻璃相,故随SiO2添加量增加而下降;陶瓷断裂韧度因棒晶裂纹桥接与裂纹偏转效应,因此也在SiO2添加量为6%时达到最高值,为15.9MPa·m1/2。Effects of different SiO_2 addition on microstructure, crystal growth and mechanical properties of Al_2O_3/33ZrO2(4Y) composites prepared by combustion synthesis under high gravity were investigated by XRD(X-ray diffraction), SEM (scanning electron microscope) and EDS (energy dispersive scalometry). The results reveal that phase constituent in the ceramic composites can not be changed with SiO_2 addition, however, with increasing in SiO_2 addition, the structure of ceramic composites is converted from cell eutectic colonies into rod-like ones, in which the length-diameter ratio of rod-like eutectic colonies is gradually raised with the decrease of volumetric fraction. As a result of the dual effects of the SiO_2 particle on viscosity of the ceramic melts, the relative density of the composites reaches the maximum value of 97.3% with 6% SiO_2 addition. Meanwhile, the hardness of ceramic composites is declined, which is attributed to the formation of SiO_2 amorphous phase in ceramic composites. In addition, due to the enhanced toughening effects of crack-bridging and crack deflection contributed by the rod-like eutectic colonies, the fracture toughness of the ceramic composites can reach up to 15.9MPa·m1/2 with 6% SiO_2 addition.

关 键 词：Al2O3/ZrO2(4Y)复合材料 燃烧合成 超重力 晶体生长 添加剂 

分 类 号：TB331[一般工业技术—材料科学与工程]